The proposed research is designed to extend the current studies of the effect of ethanol, ethanol metabolites, and related alcohols on human platelet function and metabolism. The effect of ethanol ingestion on platelet cyclic AMP levels, adenylate cyclase activity, monoamine oxidase activity, and serotonin transport will be assessed and compared to effects resulting from the addition of ethanol in vitro to normal platelets. Similarly, alterations of platelet ATPase activity produced by ethanol and ethanol metabolites will be assessed in vivo and in vitro. The effect of various compounds on the in vitro assays for antiplatelet antibody will be studied.